Heat Exchanger and Method of Exchanging Heat

ABSTRACT

A heat exchanger module includes a curved inner surface adapted to enclose at least a portion of an outside surface of a conduit. The heat exchanger module further includes a curved outer surface at least partially enclosing the curved inner surface. The heat exchanger module further includes a first port adapted to receive heat exchanger fluid and a second port spaced from the first port and adapted to exhaust heat exchanger fluid. The heat exchanger module further comprises a plurality of curved flow guides disposed between the curved inner surface and the curved outer surface. The curved flow guides are disposed between the first and second ports and they define a closed flow path between the first port and the second port.

FIELD OF DISCLOSURE

The present subject matter relates to an apparatus, assembly, and methodfor exchanging heat.

BACKGROUND

In some industrial, commercial, or residential settings, there may bepipes, ducts or other conduits that transport a hot fluid. The hot fluidmay be a hot exhaust gas from a furnace, a hot water heater, a componentused in an industrial process, or the like. It may be advantageous insome instances to use a heat exchanger to capture heat from the hotfluid and transfer it to a cool fluid. The cool fluid may be cool air tobe heated for environmental or industrial process purposes, water thatmust be heated for use as tap water or for use in an industrial process,etc. Generally speaking, existing heat exchangers are coil-shaped tomaximize the surface area available for heat exchange and are disposedinside the hot fluid conduit. The heat exchanger is connected to a fluidcircuit that supplies a heat exchange fluid that flows through the heatexchanger to capture heat from the hot fluid traversing through theconduit.

Known heat exchangers can be complex and time consuming to fabricate andinstall. Also, such heat exchangers have inlet and outlet structuresforming flow paths that necessarily pass through the walls of the hotfluid conduit, requiring sealing component(s) that can fail resulting inthe escape of hot fluid from the conduit. This escape can beunacceptable given the presence of toxic substances therein, such ascarbon monoxide in the case of combusted flue gas. Still further, afailure in a weld, for example, in the heat exchanger requires the heatexchanger to be removed from the hot fluid conduit, or at least exposedinside the conduit, so that access can be had thereto for repair. Asshould be evident, gaining such access is typically a difficult and timeconsuming process.

SUMMARY

According to one aspect, a heat exchanger module includes a curved innersurface adapted to enclose at least a portion of an outside surface of aconduit. The heat exchanger module further includes a curved outersurface at least partially enclosing the curved inner surface. The heatexchanger module further includes a first port adapted to receive heatexchanger fluid and a second port spaced from the first port and adaptedto exhaust heat exchanger fluid. The heat exchanger module furthercomprises a plurality of curved flow guides disposed between the curvedinner surface and the curved outer surface. The curved flow guides aredisposed between the first and second ports and they define a closedflow path between the first port and the second port.

According to another aspect a heat exchanger includes a plurality ofsubstantially identical and separate heat exchanger modules. Each heatexchanger module includes at least one surface defining at least onethermally conductive closed flow path extending between an inlet portand an outlet port. The at least one thermally conductive flow path hasa serpentine shape in a first dimension and has a shape in a seconddimension adapted to conform at least substantially to a particularshape. The heat exchanger further comprises connection elements adaptedto couple the plurality of heat exchanger modules to one another influid communication. The connection elements are further adapted tocouple the plurality of heat exchanger modules about and in heattransfer relationship with an outer surface of a conduit of theparticular shape.

According to yet another aspect, a method of exchanging heat includesarranging a first heat exchanger module around an outside surface of aconduit. The method further includes arranging a second heat exchangermodule adjacent the first heat exchanger module to form a first bandthat substantially surrounds the outside surface of a conduit. Themethod further includes arranging a second band substantially identicalto the first band along a length of the conduit.

Other aspects and advantages will become apparent upon consideration ofthe following detailed description and the attached drawings whereinlike numerals designate like structures throughout the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a heat exchanger comprised of a pluralityof heat exchanger modules arranged around an outside surface of aconduit that transports a hot fluid, with other devices shown inschematic view;

FIG. 1A is an enlarged view of two adjacent ports of two adjacent heatexchanger modules, wherein the two ports are connected by a connectionmember;

FIG. 1B is an enlarged view of two adjacent ports of two adjacent heatexchanger modules, wherein the two ports are adapted to interfit withone another;

FIG. 2 is an isometric view of a heat exchanger module of the heatexchanger;

FIG. 2A is a plan view of the heat exchanger module;

FIG. 2B is a side elevational view of the heat exchanger module;

FIG. 2C is a front elevational view of the heat exchanger module withflow guides of the heat exchanger module shown in dotted line through aninner curved plate of the heat exchanger module, wherein the curved heatexchanger module is shown in flattened form for clarity;

FIG. 3 is an enlarged plan view of one of the flow guides of the heatexchanger module;

FIG. 3A is a front elevational view of the flow guide of the heatexchanger module;

FIG. 4 is a plan view of two adjacent flow guides of the heat exchangermodule;

FIG. 5 is a front elevational view of a second embodiment of the heatexchanger module with flow guides and a vertical spine for creating twoflow paths shown in dotted line through an inner curved plate of thesecond embodiment of the heat exchanger module, wherein the curved heatexchanger module is shown in flattened form for clarity;

FIG. 5A is an isometric view of the second embodiment of a heatexchanger module of the heat exchanger;

FIG. 5B is a side elevational view of the second embodiment of the heatexchanger module;

FIG. 5C is a plan view of the second embodiment of the heat exchangermodule;

FIG. 6 is an enlarged plan view of one of the flow guides of the secondembodiment of the heat exchanger module;

FIG. 7 is a plan view of two adjacent flow guides of the secondembodiment of the heat exchanger module;

FIG. 8 is a plan view of a vertical spine of the second embodiment ofthe heat exchanger module;

FIG. 8A is a side elevational view of the vertical spine of the secondembodiment of the heat exchanger module;

FIG. 9 is an isometric view of a tube-like third embodiment of the heatexchanger module;

FIG. 10 is a flowchart of a method of exchanging heat by arranging heatexchanger modules around an outside surface of a conduit for hot fluid;

FIG. 11 is an isometric view of a heat exchanger module arranged aroundan outside surface of a conduit for hot fluid;

FIG. 12 is an isometric view of the heat exchanger module of FIG. 11disposed opposite from another heat exchanger module to form a firstband that substantially surrounds the outside surface of the conduit;

FIG. 13 is an isometric view of a plurality of bands, each made of twoheat exchanger modules disposed opposite from one another, with a portof one heat exchanger module being connected by a connecting member to aport of a downstream or upstream heat exchanger module; and

FIG. 14 is an isometric view of the bands of heat exchanger moduleswrapped in insulation, with other devices shown in schematic view.

DETAILED DESCRIPTION

FIG. 1 shows a thermal source 44 such as a furnace in fluidcommunication with a conduit 48 that transports hot fluid 52 from thethermal source 44 along a primary fluid circuit 56. The conduit 48 hasan outside surface 58, as further shown in FIG. 1. The hot fluid 52 maybe a hot gas or a hot liquid. A heat exchanger 60 that is adapted toextend about the conduit 48 is comprised of a plurality of bands 64arranged along a length of the conduit 48, with each band 64 preferablyincluding at least one, and more preferably at least two substantiallyor completely identical and separate heat exchanger modules 68 disposedopposite from one another and at least partially surrounding the conduit48, as further shown in FIG. 1. The heat exchanger modules 68 of theheat exchanger 60 are in fluid communication with one another, togetherwith a pump 72 and one or more additional devices, such as aconventional heat exchanger 76, to form a secondary fluid circuit 80, asshown in FIG. 1. As the pump 72 supplies a heat exchanger fluid underpressure through the secondary fluid circuit 80, heat exchanger fluidtraversing through the heat exchanger modules 68 absorbs heat from theconduit 48. The heat in the heat exchanger fluid is preferablytransferred to a thermal destination via another device, fluid,environment (ambient or another), or the like. In the illustratedembodiment, the conventional heat exchanger 76 transfers heat from theheat exchanger fluid of the secondary fluid circuit 80 to a fluidflowing through a tertiary fluid circuit 84 so that a thermaldestination 88 that is connected to the tertiary fluid circuit 84 canreceive heat. The thermal destination 88 may be, for example, a watertank that stores water to be heated. In this way, the heat exchanger 60provides an improvement in energy efficiency by capturing the heat ofthe fluid flowing through the conduit 48 that would otherwise be lost.

One embodiment of the heat exchanger modules 68 of the heat exchanger 60is shown in greater detail in FIG. 2, it being assumed that the wall ofthe conduit 48 is thermally conductive and has a circular cross sectionthat is substantially constant for at least a portion of the length ofthe conduit. The heat exchanger module 68 illustrated in FIG. 2 includesa curved inner plate 92 having a semi-circular shape in cross sectionand a curved outer plate 96 having a semi-circular shape in crosssection. The curved inner plate 92 has a curved inner surface 98 thatforms a concave face of the module 68 that is adapted to enclose atleast a portion of the outside surface 58 of the conduit 48. Preferably,the radius of curvature of the curved inner surface 98 is at leastsubstantially equal to the radius of curvature of the outside surface 58of the conduit 48. Moreover, the curved outer plate 96 has a curvedouter surface 99 that at least partially encloses the curved innersurface 98. In the illustrated embodiment the curved outer plate 96 hasa larger radius of curvature than the curved inner plate 92, therebycreating a curved space 100 between the curved inner and outer plates 92and 96, as shown in FIG. 2A. Referring again to FIG. 2, the heatexchanger module 68 further includes first and second elongate endplates 104 a, 104 b, respectively. As shown in FIG. 2, the first endplate 104 a extends between the curved inner plate 92 and the curvedouter plate 96 at one circumferential end of the heat exchanger module68. The second end plate 104 b extends between the curved inner plate 92and the curved outer plate 96 at the other circumferential end of theheat exchanger module 68.

As further shown in FIG. 2, the heat exchanger module 68 includes acurved end member 108 disposed atop the curved inner plate 92 and thecurved outer plate 96 at one axial end of the module 68. The curved endmember 108 has an upper wall 112 that extends from the curved innerplate 92 to the curved outer plate 96 radially along the heat exchangermodule 68, as shown in FIG. 2B. The curved end member 108 thus comprisesa top cover of the heat exchanger module 68 when the heat exchangermodule is oriented as shown in FIG. 2B. The curved end member 108further comprises a first port or opening 116 adapted to receive orexhaust a heat exchanger fluid such as thermal oil or water, eitheralone or in combination with one or more of ethylene glycol, ethylalcohol, propylene glycol, glycerol, or the like together with one ormore known anti-corrosion agents, flowing through the heat exchanger 60.As further shown in FIG. 2, the heat exchanger module 68 furtherincludes a second curved end member 120 disposed at bottom edges of thecurved inner plate 92 and the curved outer plate 96. The curved endmember 120 has a lower wall 124 that radially extends from the curvedinner plate 92 to the curved outer plate 96 along the heat exchangemodule 68, as shown in FIG. 2B. In this way, the curved end member 120comprises a bottom cover of the heat exchanger module 68, when themodule 68 is oriented as shown in FIG. 2B. The curved end member 108further comprises a second port or opening 128 adapted to receive orexhaust a heat exchanger fluid flowing through the heat exchanger 60. Asshown in FIG. 2, the port 116 is spaced from the port 128. In this way,the space 100 is enclosed by the curved inner plate 92, curved outerplate 96, the end plates 104, and the curved end members 108, 120. Twoor more of the elements 92, 96, 104, 108, 120 may be integral with oneanother and/or such elements may be secured together in any suitablefashion, such as by welding, brazing, one or more fasteners, or thelike.

As further shown in the embodiment of FIG. 2C, the heat exchanger module68 further comprises a plurality of arcuate or curved flow guides 132disposed between the curved inner plate 92 and the curved outer plate96. The flow guides 132 are disposed at spaced axial locations betweenthe port 116 and the port 128 and define a closed flow path between theport 116 and the port 128. Preferably, the flow guides are disposed atequidistant axial locations, although this need not be the case. Asshown in FIG. 3, each flow guide 132 has an arcuate length short of asemi-circle such that a gap 136 is created at one end of the flow guide132. The flow guides 132 are arranged within the module 68 such that thegap 136 is disposed at alternate circumferential ends of the module 68for successive flow guides 132, as shown in FIG. 4. The alternatingnature of the gaps 136 of the flow guides 132 creates a back-and-forthor serpentine flow path 134 for the heat exchanger fluid, as shown inFIG. 2C. As shown in FIG. 3A, the curved flow guides 132 are thin plateshaving a flat surface 138 that is disposed substantially perpendicularlyto the curved inner plate 92 and the curved outer plate 96, as shown inFIG. 2C. To fit within the space 100, the flat surface 138 of the curvedflow guide 132 has a width substantially identical to a distance betweenthe curved inner plate 92 and the curved outer plate 96. The flow guides132 are integral with or are secured to and/or sealed against an outersurface 139 of the curved inner plate 92 (shown in FIG. 2A) and to aninner surface 140 of the curved outer plate 96 (shown in FIG. 2A) in anysuitable fashion, such as by one or more of welding, brazing,compression sealing, fasteners, adhesive, or the like.

In operation, the module 68 (and, optionally, other modules 68fluidically interconnected therewith as noted in greater detailhereinafter) are secured to the outer surface 58 of the conduit 48 suchthat the inner surface 98 is in intimate thermal contact with the outersurface 58 of the conduit 48, as shown in FIG. 1. The module(s) 68 aremaintained in place on the conduit 48 by any suitable means, such as bystraps, bands, clamps, cable ties, or the like. Thus, as shown in theembodiment of FIG. 2C, the heat exchanger fluid enters the heatexchanger module 68 at the port 128 and flows to the right underpressure toward a gap 136 of a first flow guide 132. The gap 136 isdisposed at a circumferential end of the first flow guide 132 shown onthe right side of FIG. 2C. The heat exchanger fluid flows through thegap 136 and flows leftward toward a gap 136 of a second flow guide 132.Furthermore, the heat exchanger fluid flows through the gap 136 of thesecond guide 132 and flows rightward toward a gap 136 of the third flowguide 132, as shown in FIG. 2C. The heat exchanger fluid zig-zags (orflows in a serpentine, looping, winding, or twisting manner) in thismanner through a back-and-forth or serpentine flow path 134 formed bythe twenty-one (21) flow guides 132 that are spaced between the curvedend member 120 and the curved end member 108, as further shown in FIG.2C. As should be evident, any appropriate number of flow guides 132 canbe used within the heat exchanger module 68 to create the flow path 134.

As the heat exchanger fluid is traversing the flow path 134 defined bythe flow guides 132, the heat exchanger fluid absorbs heat from theconduit 48 and the temperature of the heat exchanger fluid rises as aresult. As further shown in FIG. 2C, the heat exchanger fluid flowsthrough a gap 136 at the rightward end of the uppermost flow guide 132,flows leftward toward the port 116, and exits the heat exchanger module68 at the port 116. In this way, heat is transferred from the hot fluid52 to the conduit 48 at least by convection, from the conduit 48 to thecurved inner plate 92 at least by conduction (the conduit 48 and thecurved inner plate 92 preferably intimately contact one another oversubstantially all of the surface area of the curved inner plate 92), andfrom the curved inner plate 92 to the heat exchanger fluid at least byconvection as the heat exchanger fluid is traversing the flow path 134from the port 128 to the port 116.

In the illustrated embodiment of FIG. 2C, the port 128 is used as aninlet and the port 116 is used as an outlet. In some embodiments, theport 128 can be used as an outlet and the port 116 can be used as aninlet. Furthermore, in the illustrated embodiment of FIG. 2C, the port128 and the port 116 are disposed on the same circumferential end of theheat exchanger module 68, meaning both are proximal one end plate of theend plates 104 a, 104 b. In other embodiments, the port 128 and the port116 can be disposed at opposite circumferential ends, meaning each isproximal to a different end plate 104 a, 104 b.

Since the heat exchanger fluid absorbs heat by convection, it isadvantageous to provide a large magnitude of thermal coupling betweenthe outer surface 58 of the conduit 48 and the curved inner plate 92 andbetween the curved inner plate 92 and the heat exchanger fluid in orderto increase heat transfer from the conduit 48 to the heat exchangerfluid. One way to accomplish this is to have a serpentine flow path suchas the flow path 134 shown in FIG. 2C, which ensures that the heatexchanger fluid contacts a substantial portion or virtually the entiretyof the curved surface of the inner plate 92, as further shown in FIG.2C.

In the illustrated embodiment of FIG. 2C, the serpentine flow path 134snakes in a longitudinal direction of the conduit 48 (i.e., the axialdirection in the illustrated embodiment, although other embodiments canbe used with conduits that are not circular in cross section) when theheat exchanger module 68 is positioned about the conduit 48. In anotherembodiment, a serpentine flow path 134 may snake in a circumferentialdirection of the conduit 48. In such other embodiment the inlet andoutlet ports of such a heat exchanger module may be disposed atdiagonally opposed corners of the heat exchanger module or at the samecircumferential end of the heat exchanger module.

As shown in FIG. 1, two sets of four substantially identical andseparate heat exchanger modules 68 a-1 through 68 a-4 and 68 b-1 through68 b-4 of the type described above (and shown in FIG. 2) are positionedalong a length of the conduit 48. Specifically, each heat exchangermodule 68 a is disposed in intimate thermal contact with and surroundingor enclosing roughly the left half (as seen in FIG. 1) of thecircumference of the outside surface 58 of the conduit 48. Additionally,each heat exchanger module 68 b is disposed in intimate thermal contactwith and surrounding or enclosing roughly the right half (as seen inFIG. 1) of the circumference of the outside surface 58 of the conduit48. The four heat exchanger modules 68 a and the four heat exchangermodules 68 b are fluidically interconnected together as described indetail hereinafter and together comprise modules of the heat exchanger60.

As further shown in FIG. 1, the modules 68 a-1 through 68 a-4 areconnected together in series by three connection members 144 a-144 cwhile the modules 68 b-1 through 68 b-4 are connected together in seriesby three connection members 144 d-144 f. Specifically, each connectionmember 144, such as the connection member 144 a couples a top port, forexample, a top port 116 a-1 of a first heat exchanger module 68 a-1 to abottom port 128 a-2 of a second heat exchanger module 68 a-2 disposedfarther along (i.e., above as seen in the FIG.) a length of the conduit48 in relation to the first heat exchanger module 68 a-1. The connectionmember 144 b interconnects a second top port 116 a-2 and a third bottomport 128 a-3 while the connection member 144 c interconnects a third topport 116 a-3 and a fourth bottom port 128 a-3. The connection members144 may connect two adjacent ports 116 and 128 to one another by abrazed or soldered joint, as shown in FIGS. 1 and 1A. Additionally, oralternatively, a port 128 of one heat exchanger module may include afemale end that mates with a male end of a port 116 of another heatexchange module, as shown in FIG. 1B. In the latter case, sealing may beeffectuated by an o-ring 145 and/or another seal disposed in the joint.As further shown in FIG. 1, a port 116 a-4 of the uppermost heatexchanger module 68 a-4 is coupled in fluid communication with a port128 b-1 of the uppermost complementary heat exchanger module 68 b-1 viaa connector 148 that couples the port 116 a-4 and the port 128 b-1. Theconnector 148 may be similar or identical to the connection members 144shown in FIGS. 1A and 1B with the exception that the connector 148 isU-shaped.

The four modules 68 b-1 through 68 b-4 are coupled together by theconnection members 144 d-144 f in series downstream of the modules 68a-1 through 68 a-4 in the same fashion that the connection membersinterconnect the modules 68 a.

Other interconnection schemes are possible. For example, theseries-connected modules 68 a may be coupled in parallel with theseries-connected modules 68 b by suitable use of connectors. In otherembodiments, one or more modules may be coupled in a first fluidiccircuit, one more modules may be coupled in a further fluidic circuit,and so on, wherein each circuit is coupled to a pump that may or may notbe shared by one or more other fluidic circuits. Generally, anyinterconnection scheme may be used with any number of fluidic circuits,as necessary or desirable.

As further shown in FIG. 1, the heat exchanger 60 further comprises twoC-shaped connectors 152, one for connecting the port 128 a-1 of thelowermost heat exchanger module 68 a-1 to the secondary circuit 80 (forexample, for receiving heat exchanger fluid under pressure) and theother for connecting the port 116 b-4 of the lowermost complementaryheat exchanger module 68 b-4 to the secondary circuit 80 (for example,for exhausting heat exchanger fluid). Furthermore, the heat exchangercomprises circumferential securement members 156 in the form ofring-shaped straps (or other suitable devices as noted above) to securea heat exchanger module 68 to a complementary heat exchanger module 68 aand to secure both modules 68 and 68 a to the conduit 48 to form a band64 of the heat exchanger 60. It should be understood that connectionelements including the connection members 144, the U-shaped connector148, the C-shaped connectors 152, and the securement rings 156 are onlyone example of connection elements that are adapted to couple the heatexchanger modules 68 a, 68 b in fluid communication with one another andin heat transfer relationship about the conduit 48.

The plurality of substantially identical and separate heat exchangermodules 68 a, 68 b that are secured in this manner by the connectionelements include at least one surface defining at least one thermallyconductive closed flow path extending between an inlet port and anoutlet port, wherein the at least one thermally conductive flow path hasa serpentine shape in a first dimension and has a shape in a seconddimension adapted to conform at least substantially to a particularshape of a conduit. The at least one surface may be one of the flatsurfaces 138 of one of the flow guides 132 of FIG. 2C. The flow path 134is an example of a thermally conductive closed flow path defined by theflat surfaces 138, as shown in FIG. 2C. The flow path 134 extendsbetween an inlet port 128 and an outlet port 116 of the heat exchangermodule 68, for example. As shown in FIG. 2, the flow path 134 has acurved semi-circular shape adapted to conform at least substantially tothe shape of the conduit 48 in an x dimension. Furthermore, as shown inFIG. 2C, the flow path 134 has a serpentine shape in a y dimension.

In this manner, the heat exchanger 60 shown in FIG. 1 facilitates thetransfer of heat from the hot fluid 52 to the heat exchanger fluid. Theheat exchanger fluid transfers the heat to the conventional heatexchanger 76 via the secondary circuit 80, as shown in FIG. 1.Furthermore, the heat exchanger 76 transfers the heat to a thermaldestination 88 via the tertiary circuit 80, as further shown in FIG. 1.

It should be noted that the heat exchanger 60 shown in FIG. 1 can haveany number of bands 64 of heat exchanger modules 68. To achieveincreased heat transfer, the heat exchanger 60 may include an increasednumber of bands 64 of heat exchanger modules 68 that absorb heat from agreater surface area of the conduit 48. To achieve decreased heattransfer, the heat exchanger 60 may include a decreased number of bands64 of heat exchanger modules 68. Furthermore, it is not necessary thatthe heat exchanger fluid traverse the modules 68 a up the left side ofthe conduit 48 shown in FIG. 1 and traverse the modules 68 b down theright side of the conduit 48 shown in FIG. 1. Instead, in an alternativeembodiment, the heat exchanger fluid may first traverse the modules 68 band thereafter traverse the modules 68 a.

Moreover, while each of the bands 64 shown in FIG. 1 comprises two heatexchanger modules 68 a, 68 b that together form a sheath or ring aroundthe conduit 48, the quantity of heat exchanger modules used to form theband 64 around the conduit 48 may be 3, 4, or another suitable quantity.For example, four heat exchanger modules, each having a quarter-circleshape can be arranged to form a band 64 that substantially surrounds theconduit 48.

One advantage of the heat exchanger 60 is that since the heat exchanger60 is in the form of a sheath disposed on the outside surface of theconduit 48 (as shown in FIG. 1), there is no need to modify the conduitto provide a volume of space within the conduit 48 specifically for heattransfer, as is the case with some conventional heat exchangers.Furthermore, the ability to remove increasing amounts of heat by addingmodules to the outside of the conduit 48 means that adequate heattransfer may be accomplished without the need for high heat exchangerfluid flow rates that, in turn, can only be effectuated by high pumppressures. Thus, the risk of dangerous pressure build-up in the heatexchanger fluid flow path is reduced or eliminated. Pressure dropswithin the conduit 48 are also advantageously eliminated.

In one embodiment, the heat exchanger 60 shown in FIG. 1 may includeheat exchanger modules 68 a, 68 b that are sized to conform to a conduit48 that has a diameter of 12 inches. Alternatively, the heat exchangermodules 68 a, 68 b are sized to conform to a conduit 48 that has adiameter of 24 inches, or any other size conduit 48. Furthermore, therelative sizes of various parts of the heat exchange modules 68 a, 68 bcan be modified to achieve desired levels of heat transfer. For example,the distance between the curved inner plate 92 and the curved outerplate 96 and/or the distances between adjacent flow guides 132 may beincreased or decreased. It should be noted that the heat exchangermodules 68 a, 68 b and the connection elements of the heat exchanger 60can be made of copper, composite material, or another appropriatematerial.

Referring again to FIG. 1, the pump 72 supplies heat exchanger fluidunder pressure through a secondary fluid circuit 80, which includes theserpentine flow paths 134 of the modules 68 a, 68 b of the heatexchanger 60. The pump 72 may further comprise a control system that canbe used to control the flow rate of the heat exchanger fluid through thesecondary circuit 80. Controlling the flow rate, in turn, determinescertain aspects of the heat transfer from the conduit 48 to the heatexchanger 60. For example, decreasing the flow rate of the heatexchanger fluid results in a higher temperature of the heat exchangerfluid because each cubic foot of heat exchanger fluid gains thermalinteraction with the conduit 48 for a longer period of time before beingexpelled from the heat exchanger 60. A heat exchanger 60 with such a lowflow rate is desirable in some situations. Following the same rationale,increasing the flow rate of the heat exchanger fluid results in a lowertemperature of the heat exchanger fluid, which may be desirable in othersituations. As an example, the conduit 48 of FIG. 1 may contain a gashaving a temperature of eight-hundred (800) degrees Fahrenheit and theheat exchanger fluid may be water that is driven through the heatexchanger 60 at such a flow rate that the water maintains a temperatureof eighty (80) degrees Fahrenheit, for example. In this way, theadjustability, modularity, and simple design of the heat exchanger 60allows it to be used in a variety of contexts that have different heattransfer needs.

Different types of heat exchanger modules 68 can be used as parts of theheat exchanger 60. For example, the heat exchanger 60 may comprise aplurality of substantially identical and separate heat exchanger modules68 c of the type shown in FIG. 5. Generally speaking, the heat exchangermodule 68 c of FIG. 5 is substantially identical to the heat exchangermodule 68 described above (and shown in FIG. 2C) except that the heatexchanger module 68 c encloses two separate serpentine flow paths 134c-1 and 134 c-2 instead of one serpentine flow path. The two serpentineflow paths 134 c-1, 134 c-2 are adjacent one another and each occupyabout half of the space 100 c enclosed by the heat exchanger module 68c, as further shown in FIG. 5. The heat exchanger module 68 c includestwo inlet ports 128 c and two outlet ports 116 c, with each flow path134 c-1 and 134 c-2 having its own inlet port 128 c and its own outletport 116 c. In other respects, the heat exchanger module 68 c isidentical to the heat exchanger module 68 of FIG. 2, as shown in FIGS.5A, 5B, and 5C. The heat exchanger module 68 c further includes adivider 157 (shown in FIGS. 8 and 8A) comprising an elongate plate thatextends between upper wall 112 c and lower wall 124 c, as shown in FIG.5. The divider 157 is further disposed transverse to the inner curvedplate 92 c such that the space 100 c is divided into two. The heatexchanger module 68 c includes two sets of curved flow guides 132 c, oneset being disposed on one side of the divider 157 and defining the firstflow path 134 c-1 and the other set being disposed on the other side ofthe divider 157 and defining the second flow path 134 c-2, as shown inFIG. 5. Each set of curved flow guides 132 c includes a plurality ofcurved flow guides 132 c spaced apart from one another from the upperwall 112 c to the lower wall 124 c.

Referring now to FIG. 6, each flow guide 132 c is a curved plate thathas an arcuate length somewhat short of a quarter-circle, therebyleaving a gap 136 c through which heat exchanger fluid can flow. Theflow guides 132 c of each set of curved flow guides 132 c are arrangedbetween the upper wall 112 c and the lower wall 124 c such that the gap136 c is positioned alternatively proximal the divider 157 and proximalan end plate of the end plates 104 c-1, 104 c-2. In other words, eachsuccessive flow guide 132 c is positioned such that a gap 136 c of oneflow guide 132 c is located at a different end than a gap 136 c of aflow guide 132 c immediately above or below the one flow guide 132 c, asshown in FIG. 7. The first and second set of flow guides 132 c arearranged with gaps 136 c that alternate in this manner to define firstand second flow paths 134 c-1, 134 c-2, respectively, as shown in FIG.5. A first flow of heat exchanger fluid enters at the inlet port 128 cshown on the left side of FIG. 5 and exits via an outlet port 116 cshown on the left side of FIG. 5. A second flow of heat exchanger fluidenters at the inlet port 128 c shown on the right side of FIG. 5 andexits via an outlet port 116 c on the right side of FIG. 5.

In some instances, a heat exchanger 60 having two flow paths 134 c-1,134 c-2 as described above may provide increased heat transfer from theconduit 48 to the heat exchanger 60 because twice as much heat exchangerfluid can be circulated through the double-path heat exchanger 60 incomparison with a single-path heat exchanger 60. In some situations, theheat exchanger 60 having two flow paths 134 c-1, 134 c-2 can maintain agreater temperature differential between the hot fluid 52 and the heatexchanger fluid. For example, the double-path heat exchanger 60 maymaintain the heat exchanger fluid at seventy (70) degrees Fahrenheitwhile the hot fluid 52 has a temperature of eight-hundred (800) degreesFahrenheit. It should be noted that the heat exchanger 60 comprised ofheat exchanger modules 68 c can be modified, controlled, or modularlyextended in a substantially identical manner as a heat exchanger 60 ofmodules 68 of FIG. 2C and also may have substantially identicaladvantages.

In another embodiment, the heat exchanger 60 may comprise a plurality ofsubstantially identical and separate heat exchanger modules 68 d of thetype shown in FIG. 9. The heat exchanger module 68 d of FIG. 9 has aflow path 134 d that has a shape substantially identical to the flowpath 134 but the heat exchanger module 68 d forms this flow path 134 dusing a tube-like structure 158 rather than a tank-like heat exchangermodule that has plates and gaps within to define a flow path. A heatexchanger 60 comprises a plurality of heat exchanger modules 68 d, eachhaving a tube-like structure 158 that includes at least one surfacedefining at least one closed flow path 134 d extending between an inletport 128 d and an outlet port 116 d. The tube-like structure 158 is madeof a thermally conductive material such that the flow path 134 d isitself thermally conductive to allow heat exchanger fluid to absorbheat. The tube-like structure 158 has a serpentine or zig-zag shape in afirst dimension y shown in FIG. 9 and has a shape in a second dimensionx adapted to conform at least substantially to a conduit having aparticular shape. In this instance, the tube-like structure 158 has asemi-circular or curved shape in the x dimension to conform to a conduitthat has a cylindrical shape.

The heat exchanger 60 having a tube-like heat exchanger module 68 d mayfurther include connection elements adapted to couple the plurality ofheat exchanger modules 68 d to one another in fluid communication. Theseconnection elements may be the connection members 144 and the U-shapedconnector 148 shown in FIG. 1 and described in connection with FIG. 1.The connection elements may further be adapted to couple the heatexchanger modules 68 d about and in heat transfer relationship with anouter surface of a conduit having a particular shape. For example, thesecurement ring 156 (shown in FIG. 1) may secure bands of modules 68 dabout and in heat transfer relationship with an outer surface 58 of theconduit 48 (again, shown in FIG. 1) that has a cylindrical shape. Itshould be noted that the heat exchanger 60 comprised of tube-like heatexchanger modules 68 d can be modified, controlled, or modularlyextended in a substantially identical manner as the heat exchanger 60 ofFIG. 1 and also may have substantially identical advantages.

A flowchart for a method 160 of exchanging heat by arranging heatexchanger modules around an outside surface of a conduit for hot fluidis shown in FIG. 10. As shown in FIG. 10, the method 160 may include astep of arranging a first heat exchanger module around an outsidesurface of a conduit (FIG. 10—block 180). For example, a complementaryheat exchanger module 68 b-4 is arranged around the outside surface 58of the conduit 48 shown in FIG. 11. As further shown in FIG. 10, themethod 160 may further include a step of arranging one or moreadditional heat exchanger modules adjacent the first heat exchanger toform a first band that substantially surrounds the outside surface ofthe conduit (FIG. 10 block 200). For example, a heat exchanger module 68a-1 is arranged adjacent and opposite to the complementary heatexchanger module 68 b-4 to form a first band 64, as shown in FIG. 12. Asfurther shown in FIG. 10, the method 160 may further include a step ofsecuring the first band to the conduit (FIG. 10—block 220). For example,a securement ring 156 may be wrapped around the pair of heat exchangermodules 68 a-1, 68 b-4 and tightened until the band 64 of heat exchangermodules 68 a-1, 68 b-4 is secured to the conduit 48, as further shown inFIG. 12. In this way, a lowermost band 64 is secured to the conduit 48.

As further shown in FIG. 10, the method 160 of exchanging heat mayfurther include arranging one or more additional bands along a length ofthe conduit (FIG. 10—block 240). The one or more additional bands 64 maybe arranged upstream or downstream of the first band 64 and may bearranged using a process substantially identical to the process used toarrange the lowermost band 64, which is shown in the blocks 180, 200,and 220. As shown in FIG. 13, three additional bands 64 are arranged andsecured along the length of the conduit 48 in this manner.

As further shown in FIG. 10, the method 160 of exchanging heat mayfurther include connecting a port of a first heat exchanger module witha port of a downstream or upstream heat exchanger module to create aflow path (FIG. 10—block 260). For example, as further shown in FIG. 13,connection member 144 a couples an outlet port 116 a-1 of a first heatexchanger module 68 to an inlet port 128 a-2 of another heat exchangermodule 68 a-2 immediately above the first heat exchanger module 68 a-1.In addition, the method 160 may include securing a U-shaped or othersuitably shaped connector 148 to adjacent ports 116 a-4, 128 b-1 ofrespective adjacent heat exchanger modules 68 a-4, 68 b-1, as shown inFIG. 13. In this way, a flow path 134 is created that traverses theeight heat exchanger modules 68 a, 68 b of the heat exchanger 60.

The method 160 may further include connecting the flow path to a thermaldestination (FIG. 10—block 280). This step may include coupling an inletport 128 a-1 of the lowermost heat exchanger module 68 a-1 to one end ofa secondary fluid circuit 80 using a C-shaped or other suitably shapedconnector 152, as shown in FIG. 1. Moreover, this step may includecoupling an outlet port 116 b-4 of the lowermost heat exchanger module68 b-4 to another end of a secondary fluid circuit 80 using anotherC-shaped or other suitably shaped connector 152, as further shown inFIG. 1. The secondary fluid circuit 80 may include a pump 72 thatprovides heat exchanger fluid under pressure into the bottom port 128a-1 of the lowermost heat exchanger module 68 a-1 such that the heatexchanger fluid is expelled at the outlet port 116 b-4 of the lowermostheat exchanger module 68 b-4. The secondary circuit may further includea conventional heat exchanger 76 that is in turn in fluid communicationwith the thermal destination 88 via a tertiary fluid circuit 84, asfurther shown in FIG. 1.

The method 160 may further include wrapping the bands of heat exchangermodules with insulation (FIG. 10—block 300). For example, a sheath ofinsulation 304 may be wrapped around the four bands 64 that make up theheat exchanger 60, as shown in FIG. 14. As further shown, insulating theheat exchanger 60 in this manner reduces heat loss from the heatexchanger 60 to the surrounding air thereby improving the efficiency ofheat transfer from the conduit 48 to the thermal destination 88.

It should be noted that the method 160 can be carried out using any oneor more of the alternative or modified heat exchanger modules describedherein. For example, the method 160 can be carried out using thesingle-path heat exchanger module 68 of FIG. 2C, any modificationthereof, the double-path heat exchanger module 68 c of FIG. 5, anymodification thereof, the tube-like heat exchanger module 68 d, or anymodification thereof, or any combination of these or other suitable heatexchanger modules.

The advantages of the method 160 of exchanging heat by arranging heatexchanger modules around an outside surface of a conduit for hot fluidand of the heat exchanger 60 itself are numerous. One advantage is thatinstallation or replacement of the heat exchanger 60 is not costly ortime consuming because it does not require cutting out a portion of theconduit 48 or any other modification to the conduit 48. In addition,since the conduit 48 is not substantially modified, whatever functionthe conduit 48 is providing can continue without interruption while theheat exchanger 60 is being installed or replaced. In addition, themodularity of the heat exchanger 60 allows for substantial changes tothe magnitude of heat transfer without substantial modifications to theconduit 48.

INDUSTRIAL APPLICABILITY

In summary, a heat exchanger adapted to conform to an outside surface ofa conduit for a hot fluid provides ease of adjustability regardingmagnitude of heat transfer, lower manufacturing costs, and reduction ofrisks associated with conventional heat exchangers. In addition, amethod of exchanging heat by arranging heat exchanger modules around anoutside surface of a conduit for hot fluid provides easy installationand maintenance.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar references inthe context of describing the invention (especially in the context ofthe following claims) are to be construed to cover both the singular andthe plural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the disclosure and does not pose alimitation on the scope of the disclosure unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the disclosure.

Numerous modifications to the present disclosure will be apparent tothose skilled in the art in view of the foregoing description. It shouldbe understood that the illustrated embodiments are exemplary only, andshould not be taken as limiting the scope of the disclosure.

1. A heat exchanger module, comprising: a curved inner surface adaptedto enclose at least a portion of an outside surface of a conduit; acurved outer surface at least partially enclosing the curved innersurface; a first port adapted to receive heat exchanger fluid; a secondport spaced from the first port and adapted to exhaust heat exchangerfluid; and a plurality of curved flow guides disposed between the curvedinner surface and the curved outer surface and disposed between thefirst and second ports, the flow guides defining a closed flow pathbetween the first port and the second port, wherein each of theplurality of flow guides extends circumferentially with respect to theoutside surface of the conduit, wherein each curved flow guide has anarcuate length short of a semi-circle such that a gap is created todefine the closed flow path, wherein the plurality of flow guides arearranged such that the gap is disposed at alternate circumferential endsof the heat exchanger module for each successive flow guide to define aserpentine shape of the closed flow path.
 2. The heat exchanger moduleof claim 1, wherein the closed flow path defined by the flow guides isserpentine in one dimension and has a semi-circular shape adapted toconform to the outside surface of the conduit in a second dimension. 3.The heat exchanger module of claim 1 in combination with at least oneother substantially identical and separate heat exchanger module to forma band of a heat exchanger.
 4. The heat exchanger module of claim 1 incombination with at least one other substantially identical and separateheat exchanger module, wherein the heat exchanger module and the atleast one other heat exchanger module are in fluid communication withone another.
 5. The heat exchanger module of claim 1, wherein the curvedinner surface and the curved outer surface each have a semi-circularshape.
 6. (canceled)
 7. (canceled)
 8. The heat exchanger module of claim1, wherein the plurality of curved flow guides are a first plurality ofcurved flow guides, the heat exchanger module further comprising: asecond plurality of curved flow guides; a divider disposed transverse tothe curved inner surface, wherein the first plurality of curved flowguides are disposed on a first side of the divider and wherein a secondplurality of curved flow guides are disposed on a second side of thedivider.
 9. The heat exchanger module of claim 8, wherein the closedflow path is a first closed flow path, the heat exchanger module furthercomprising: a third port adapted to receive heat exchanger fluid; and afourth port spaced from the third port and adapted to exhaust heatexchanger fluid, wherein the second plurality of curved flow guides aredisposed between the curved inner surface and the curved outer surfaceand disposed between the third and fourth ports, the second plurality ofcurved flow guides defining a second closed flow path between the thirdport and the fourth port.
 10. The heat exchanger module of claim 9,wherein each curved flow guide of the first and second pluralities offlow guides has an arcuate length short of a quarter-circle.
 11. A heatexchanger, comprising: a plurality of substantially identical andseparate heat exchanger modules wherein each heat exchanger moduleincludes at least one surface defining at least one thermally conductiveclosed flow path extending between an inlet port and an outlet port,wherein the at least one thermally conductive flow path has a serpentineshape in a first dimension along a length of a conduit and extendscircumferentially in a second dimension adapted to conform at leastsubstantially to a particular shape of an outer surface of the conduit;and connection elements adapted to couple the plurality of heatexchanger modules to one another in fluid communication, wherein theconnection elements are further adapted to couple the plurality of heatexchanger modules about and in heat transfer relationship with the outersurface of the conduit of the particular shape.
 12. The heat exchangerof claim 11, wherein the at least one surface of each heat exchangermodule is a surface of a tube-like structure that forms each heatexchanger module.
 13. The heat exchanger of claim 11, wherein the shapeof the flow path in the second dimension is semi-circular.
 14. The heatexchanger of claim 11, wherein the connection elements include asecurement ring.
 15. The heat exchanger of claim 11, further comprisinga sheath of insulation wrapped around the plurality of heat exchangermodules.
 16. A method of exchanging heat, the method comprising thesteps of: arranging a first heat exchanger module around an outsidesurface of a conduit; arranging a second heat exchanger module adjacentthe first heat exchanger module to form a first band that substantiallysurrounds the outside surface of the conduit; and arranging a secondband substantially identical to the first band along a length of theconduit, wherein each of the first and second heat exchanger modulesincludes a plurality of curved flow guides disposed therein defining aclosed flow path between a first port and a second port, wherein each ofthe plurality of curved flow guides extends circumferentially withrespect to the outside surface of the conduit, wherein each curved flowguide has an arcuate length short of a semi-circle such that a gap iscreated to define the closed flow path, wherein the plurality of flowguides are arranged such that the gap is disposed at alternatecircumferential ends of each heat exchanger module for each successiveflow guide to define a serpentine shape of the closed flow path.
 17. Themethod of claim 16, further comprising the step of connecting the firstport of the first heat exchanger module with the second port of a thirdheat exchanger module, wherein the third heat exchanger module isdisposed upstream or downstream of the first heat exchanger module alongthe length of the conduit.
 18. The method of claim 16, wherein the firstand second heat exchanger modules each include two flow paths.
 19. Themethod of claim 16, wherein the first and second heat exchanger modulesare each tube-like.
 20. The method of claim 16, further comprising thestep of coupling the first heat exchanger module to a fluid circuit thatincludes a pump.